Consortium for International Earth Science Information Network

The World Health Organization's Mortality Database

Dataset Abstract/Summary

The WHO mortality data base contains information on
cause-of-death that
is originally supplied to the Organization by those Member States
that have
universal registration of deaths in conjunction with a high level of
certification of cause-of-death. The first year of data is 1950, and the number of countries for
which
data are available varies from year to year; similarly, the existence
and
completeness of a time series of data varies by country. Approximately 50 to 60 countries report to WHO regularly. In general,
there
are fairly complete time series for more developed countries,
notably
northern America, Europe (including eastern Europe), Australia, New
Zealand,
Japan, and to a limited extent for the former USSR and newly
independent
states of the former USSR. For a number of less developed countries
there are
intermittent data sets, but some of these are also of limited
usefulness. For
other less developed countries, notably in Latin America, there are
series
that are of substantially improved quality in recent years. Outside
of Latin
America, a very few less developed countries present robust time
series.

Mortality data is comprised of the number of deaths by age group, cause of death, sex, year, and country or area. Age group is reported in one of nine different age groupings. Cause of death is coded using a three character International Classification of Disease code (ICD), internally developed and maintained by WHO. Country or area is a four digit code representing the reporting unit.

Mortality data includes several ancillary translation tables including ICD codes, WHO region, and country or area reporting unit. The data store also contains supplementary population data which is used to calculate mortality rates and other statistics.

Archival and Access Information

The Mortality Database is archived by the World Health Organization (WHO) and its contents are accessible to anyone at no charge upon request. Requests are handled by WHO representatives; currently the database itself is not accessible to others.

The attention of
the
potential user is also drawn to the fact that selected presentations
from the
data base are published in hard copy annually in the World Health
Statistics
Annual that can be found in most large public, and university
libraries. The
Annual offers the reader in particular a succinct 3-page display of
each
country-year of deaths by cause, and of age and sex-specific
mortality rates.

Dataset Variables

The units of information stored are the registered
numbers
of female and male deaths, according to age, due to a specific
cause-of-death
for a given country in a particular year, and the reported population
of that
country by age and sex, as well as the number of live births for the
same
year. The data base is now about a gigabyte in size.

The cause-of-death labels used vary over time according to the
version
of the International Classification of Diseases used. The
International
Classification of Diseases (ICD) has been revised ten times since its
first
formulation in the 19th century. The data base was established after
the
sixth revision (ICD6) of 1948. ICD7 was published in 1955, ICD8 in
1965, ICD9
in 1975, and ICD10 in 1992. Countries did not necessarily all adopt
a new
revision in the year it appeared, so the switch from one revision to
the next
is generally staggered. The total number of labels in any
Classification is
large, and cells would be quite small or empty in the case of rarer
diagnostic
categories. Consequently, none of the Classifications have been
exhaustively
applied to label causes; each Revision has an accompanying shorter
list for
purposes of parsimony and information storage. For ICD6, ICD7, and
ICD8,
there is list A (150 causes) or List B (50 causes). For ICD9, there
is the
Basic Tabulation List or BTL, that provides greater flexibility and
variability in the number of cause labels that can be utilized. In
the
special case of neoplasms, furthermore, under the provisions of ICD6,
ICD7,
ICD8, and ICD9, Member States may choose also to provide detailed
cause-of-
death data for about 100 cancer sites. ICD10 has provisions for a
condensed
list of 103 causes, or a selected list of 80 causes, as well as
specialized
lists for infant and child mortality. The degree to which equivalent
causes
may be tracked from one Revision to another depends on the stability
of a
label - the time trend for some important causes has accordingly been
well
documented - or, for labels that change, depends on the extent to
which the
causes subsumed in a label can be distinguished and tracked from
Revision to
Revision. Tracking is easier if there is tolerance for less detail,
and some
loss of information is acceptable.

The age groups employed vary by country and may vary for one
country
over time. Countries may group deaths according to five-year (or
ten-year)
age groups between 5 and 9 (or 5 and 14) years and from 60 to 64 (or
55 to 64)
years. Age groups under 5 years of age are variable; some countries
use age
0 and age 1-4 years grouped, and others use age 0 and years 1, 2, 3,
4 in
single years. Similarly, the existence and grouping of death data
for the
population over 64 varies: deaths to the older population exist
grouped for
all ages 65 and over, 70 and over, 75 and over, or 85 and over.
Furthermore,
there are combinations of the different groupings for the youngest
and oldest
ages: at present 9 age codes exist in the data base, including deaths
provided
without reference to age. Finally, the ages employed to classify
infant
deaths - deaths at age 0 years - also vary, in particular for the
neonatal
period: deaths may or may not be separately reported that occurred in
the
first 28 days, whereas in some cases, neonatal reports are complete
for deaths
on day 0, in week 1 (days 1 to 6), in the first four weeks (days
7-27), or
subsequently (days 28-364).

The sex is provided for all deaths by all countries. The fact
that
there are sex-specific causes of death (for example, prostate cancer,
ovarian
cancer, or obstetric causes) serves to help validate the data
submitted.
The population for each age-sex group is provided for each
country-year
in the data base to enable users to calculate mortality rates and
derive
measures such as life expectancies.

Data Acquisition/Collection Summary

Mortality data are based on actual death certificates, which are reported only by countries which require legal certification of death. The original data are collected at country level in the Central Statistical Offices or in the Ministries of Health from approximately 80 countries, including most developed countries, and are transmitted to the World Health Organization. Data is transmitted by member countries to WHO in a variety of formats. It is then rigorously validated. The process of validating the data includes vertical and horizontal tallying, validating for certain distributions, validating in comparison to previous years, as well as validating the data vis a vis the ICD (International Classification of Diseases) codes.